1. Field of the Invention
The present invention relates to a height-adjusting system. In particular, the present invention discloses a height-adjusting system that permits rapid rough adjustments of the extension of a supporting leg, and which further permits fine adjustments to the extensional length of the supporting leg.
2. Description of the Prior Art
Please refer to FIG. 1. FIG. 1 illustrates a typical setup for a projector 10. The projector 10 rests on a flat surface 12, such as a table, and projects an image onto a screen 14. As the height of the screen 14 may vary with respect to the projector 10, a tilt adjust system 18 is provided on the projector 10 to adjust a projection angle xcex8 of the projector 10, and hence the position of the image on the screen 14.
Please refer to FIG. 2 with respect to FIG. 1. FIG. 2 is a front view of the tilt adjust system 18 for the projector 10. The prior art tilt adjust system 18 typically consists of two legs 18L. Each leg 18L has a threaded support rod 18R, a foot 18F, and a correspondingly threaded bolt 18B. The support rod 18R screws into the bolt 18B. By turning the support rod 18R (for example, by way of the foot 18F), a relative distance d between the foot 18F and the bolt 18B may be changed, thereby changing the height of the front end of the projector 10 and hence the projection angle xcex8.
The prior art tilt adjust system 18 provides a simple and secure footing for the projector 10. However, actually changing the projection angle xcex8 can be a somewhat tedious process for the user, as it can involve turning each of the support rods 18R a great number of times. To facilitate this task, the user may place the projector 10 onto its side, so that the feet 18F are not in contact with the surface 12, and hence easier to turn. All of this is inconvenient
It is therefore a primary objective of this invention to provide a height-adjusting system for a device, such as a projector, that is easy to use and to adjust, and which provides secure footing for the device.
Briefly, the preferred embodiment of the present invention discloses a latching mechanism for a height-adjusting system. The latching mechanism includes a first housing, an internal module slidably disposed within the first housing, and a second housing that locks onto the first housing. The first housing has a bottom surface with a central opening for accepting a height-adjusting rod, a brace mounted on the bottom surface adjacent to the central opening, first and second surfaces respectively disposed on first and second sides of the first housing, and a third surface disposed on a third side of the first housing. The brace has a bracing surface that is substantially aligned with an edge of the central opening, and the bracing surface is adapted to brace the height-adjusting rod. The internal module includes a central portion having a first opening with a contact surface, first and second tabs extending respectively from first and second sides of the central portion, and a third tab extending from a third side of the central portion. The first, second and third tabs are respectively disposed over the first, second and third surfaces. The brace is disposed within the first opening. The bracing surface of the brace faces towards the contact surface on the first opening. Mechanical interaction between the first and second tabs and the first and second surfaces prevents the central portion from contacting the bottom surface so as to provide a smoother latching/unlatching action. When the central portion is in a first position, the contact surface of the first opening presses the height-adjusting rod against the bracing surface to latch the height-adjusting rod into position. When the central portion is in a second position, the contact surface of the first opening is sufficiently spaced from the bracing surface to enable the height-adjusting rod to slide between the bracing surface and the contact surface. The third tab acts as a button that a user may press to move the internal module to the second position so as to unlatch the height-adjusting rod and so quickly change the tilt angle of the projector. Both the contact surface and the height-adjusting rod are threaded, which enables the contact surface to mechanically engage with, and hence latch onto, the height-adjusting rod. When latched into position, the height-adjusting rod may be turned to permit fine adjustments to height.
It is an advantage of the present invention that by pressing the third tab as a button, the user may quickly latch and unlatch the height-adjusting rod, and so quickly change the extensional height of the height-adjusting rod. This would correspond to quick, rough adjustments to the height of the device, such as the tilt of a projector. Changing the projection angle is thus made both easier and quicker. Additionally, the action of the latching device is made smooth by the first and second tabs, as the internal module contacts the housing primarily only at the first and second tabs. Finally, as noted above, fine adjustments to the height of the device are possible by turning the height-adjusting rod.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment, which is illustrated in the various figures and drawings.